Construction of wings for aircraft



Dec. 25, 1934.- B. N. WALLIS 1,985,649

CONSTRUCTION OF WINGS FOR AIRCRAFT Filed Dec. 12, 1935 4 sheets-sheet 2Dec. 25, 1934. B. N. WALLIS CONSTRUCTION OF WII'LIGS FOR AIRCRAFT FiledDec. l2, 1935 4 Sheets-Sheet 3 DQC- 25, 1934 B. N. wA| |s CONSTRUCTIONOF WINGS FOR AIRCRAFT Filed Deo. l2, 1933 4 Sheets-Sheet 4 gam Mda-Patented Dec. 25, 1934 coNs'rRUorIoN oF WiNGs Fon AI'ltc'lciir'r` iBarnes Neville Wallis, Weybr'iag, England; as; signor to Vickers(Aviation).r Limited, Wey-f l bridge, England Application `December' 12,

M In Great Britain December 22, 1932 il; .i This invention `relates tothe construction of Wings for aircraft and aims at securing wings ofgreat rigidity and torsional stiffness. `This effect is attained bysupportingan exterior 4fabric ..5 or other thin flexible cover on anexterior lcontour frame in which the metal `comprising the torsion andshearlresisting bracing members and the longitudinalmembers is locatednear the surface ofthe wings in the position of optimum value. l Y 1 l 3According to thisinvention an upper boom and alower boomlocated at ornear (hereinafter referred to as in for brevity) t the deepest portionof the wing, together with or Without a boom located in or adjacent tothe leading ledge of the wing, and a ymember or boom in or adjacenttothe trailing edge, areheld in position by brac-V ing members havinggreaterfdepth normal to the contour `than breadth and arrangedin two'selries which cross each other, said `bracing members being formed withtheir neutral axes `as geodesics, or approximately as geodesics,` in asurface equidistant'at all points from the external surface ofthe wing.The axes of these geodetic bracing members intersect each 4zother at allpoints of crossing and'also intersect the booms and the "trailing edgememberand leading edge member where, they cross `or converge. Theupperand lower booms may bebraced or connected'to" each other. by websor other direct interconnections which combine withrthe booms to producegirders w capable of resisting vertical forces and which are maintainedrigid against torsional and horizontal forces bythe g'eodetic bracingmembers. The bracing members rare preferably symmetrical 'with respectto axes passing through the points lof intersection of said bracingmembersfparallel `to the booms;

In a modification, the webs or otherdirect'interconnections between theupper and lower booms are eliminated. The vertical shear forces are thentaken by the booms themselves assisted by the geodetic bracing members.`In such a construction it is necessary to increase-'the strength of thebooms `and/or of the geodetic bracing members, because the advantage ofdirect connection between the booms is absent.` I l A practical exampleAof wing construction according to the invention will now be describedwith reference to the accompanying drawings in whichz- A Y g i V Figure1 is a plan view of part `of a wing showing vone of the booms, thebracingmembers'and theleading and trailing edge members, but omit--`ting the `fabric covering. l

1933, seriaiNu.'102.064,'`

f Figure rsection on'thefline `2 2 in Fig- T ure .1 drawn to fanenlarged scale.

Figure 3V is a section on the line 3-3 in Figure 1 drawn to `anrenlargedscale. p t

Figure 4is 'afragmentary plan view on an enlarged scale jshowing theVjoint between the rbracing. members `andthe leading edge member.

Figure 5 is a'fsection on the line 5-5 in Figure4, Y

Figures 6 an`d 7 show in planand elevation respectively, the means for.fixing `the bracing members to the booms. t t t Figures Sand 9 showinplan and .end ele,-V vation .respectively,afitting for connecting thebracing members where `they intersect. y

- In vFigures 1 toI 3 the upperfboom` @andthe lower boom b areinterconnected,"and braced againstlverticalshear forces'by theWarrensystem diagonalsc, and braced against torsional andv horizontalshear forces in the wing structure by the two series of bracing membersarranged crosswise, .the bracing members marked d of one seriesextending in one direction while the bracing members marked` e of theother seriesextend in `the .other direction. `These crosswise bracingmembers intersect and are made insections extending from `one point ofintersection to the next.` Said bracing members are constructed of`channel section` material having their webs d1, e1Vextending...inwardly normal to the contour, and havingtheir anges d2,d3; e?, e3 extending in the direction of spanof the wing. Theintersectingtting `for rigidlyxing the; bracing membersrtogether wherethey intersect comprises two gusset plates j, f1, and a connectingpieceffzto` which extension lugs d6, es ofthe `Webs d1, `e1 andtheflanges d2, d3; e2, e3` are attached by rivets;

The bracing members which intersect the boom `are made in shortersectionsthan the remainder,

these short sections being marked d4, d5; e4, e5, respectively.` One-endof each short section is `fixed like lthe other sections `toanintersecting `fitting j, the other ends being rigidly secured togetherin pairs andv to thebooms by boom ttings each offwhch, as shown inFigures 6 and '7, con-` sists of .two opposedside plates g, g1, with aweb g2, the web being formedwith an elliptical-hole so that it canbepassed over the boom and fixed to this byopposed'lugs, one 4of Which g3extends outwardly andthe otherlof which g4 extends inwardly relativelyto the fitting. To stiffen the side' plates and enable them to `transmitthe stresses fromone section tothe' continuing section, pressedout lletsg5, qs are formedin said but, as shown, terminatezadjacent to fthesaid"edges. The terminations ofthe bra'cing members are fixed together byleading and trailing edge booms of similar construction, sothatztheleading edge boom will now be describedfby Awayof example, withparticular reference to Figures 4 and 5. The bracing members d and eof-theupper surface of the ,winglar-e received in a channel member' heXtendi'ng'in the ,direction ofspanbf the Wing, .whilerthebracingmembersdande of .the lower surfaceof the `wingarejreceived'in a similar.channel member h1.y vThe flanges of these lchannel members are arrangedto Aextend Lalong the .ends of the iianges of vthebracing' members t`o,whichth`ey Yare ,riveted andthe .webs of1 the channel members which arevertical areriveted toextensionsformed ,inthe Webs of .the bracingmembers. "The 'webs' of vthese channel members are interconnected bybracing diagonals arrangedl .on the Warren system, and are alsoprovided, v,viffh'ere the bracingimembjers meet 'on said channelmembers;- with averti'cal 'plate It? 'to whichpare xedltriangu'lar knee'pieces h? which extend in the direction of each superposed pair ofbracing. members, these 'knee ,pieces fare also fixed, at points spaced'from' the vertical plates, to the webs ,ofv each superposed pair ofvbracing members; thus forming a three point triangular connection foreach 'knee piece.` At 'the vleading edge afairing of suitable shape,indicated by h?,

`is provided. "The construction of 4the trailing ,l edgeboom beingsimilar to that of the leading edgeboom will be understood from theforegoing description, the only difference being that an aileron h ishinged tothe trailing edge boom at the outer part of thel wing, whilethe space between the aileron and 'the root of the wing is occupied by afairing piece'of suitable section indicated at h., 'Y Vi It will be.observed that, owing to the taper `of the wing, the arrangement of thebracing members has 'to b e slightly modified at the leading andtrailing edges. o .f -j Outside the ,bracing members of the structurethusr formed, stringers'maybe attached either in the direction of thespan of the wing or transversely thereto, and around the wing structurea fabric covering is applied and secured in any convenient manner. i

The construction thus obtained results, as before stated, in a wingWhichmay be regarded as an analytical structure of which the bracinginembers are bowed out so as to conform to the contour of the wing. Thegeodetic bracing members not only act as torsion and horizontal shearbracings, but also serve as f ormers for carrying the outer covering,and thus eliminate the Iusual transverse ribs and the drag and`anti-drag bracings while the material .forming .the geodetic vbracingmembers is utilized to the highest degree of efliciency,fresulting inawing of extreme light-l ness andgreat strengthA and rigidity.

- The structure before described results in a con toured Wing frame inwhich geodetic bracing members resist all torsional loads imposed on thewing in the manner of a stressed skin but without the weight necessarilyincorporated in such a stressed skin forV the purpose of resisting thecrinkling of the skin likely to be set up in withstanding torsional orexural stresses. The effect therefore is secured of a skin of greatthickness but yet of minimum weight which not only resists torsionalloads but contributes to the strength .of the wing in vother directions,thus enabling a `wing of'great strength'and stiffness to be secured for'the minimum expenditure of weight.

` Inthemodicatio'n referred to above, the construction is the' sameexcept that the Warren system diagonals cbetween the boom are eliminatedforming a wing having an interior completely free and unobstructed. Inthis modification vwhere the outer end of a wing is left open and notreduced in depth to a fine outer edge closing jthe lwingfan inner wing`of any suitable construction may be provided to slide telescopically inthe `outer wing, for example by being guided "on suitable runners, saidinner Wing being adapted vto be projected outwardly from' the outer'Wing for the purpose of increasing the wing-areawhen taking olf orlanding, when a slower 4flying speed is `desirable under a lighter wingloading'. One suchextension may be provided in each wing, or'multipleextensions which could be slidden outwardsy either simultaneously toincrease 'the span equally for eachfseoti'o'moi successively asdesiredvln such'afconstruction, the Ywing depth and chord of theentireir-in'er wing might 'remain constant while the outer 'and larger wingwhich is not adjustable but is 'perf manently fixedy'to fthe fuselagemay be'tapered from itsro'ot to its tip.v o o It win zloo understoodthat the inner wing may be built 'up with longitudinal booms (with orwithout a web "or other interconnecting'members) and'intersecting'geodetic Vbracing members 'simi'-y lar to that of the cuter a .l Theinvention is particularly applicable' to a 'cantilever'wing but is alsoapplicable to superposed 'wings which are stayed apart by nterp'lanestruts, with or without lift and anti-lift bracings',` in-order to takelifting loads and assist in resisting torsion stresses.

VAWhat I claim as my invention and'desire to of the wingha'ving agreater depth than breadth and having their depth normal to the contourat all lpoints, said bracing members being formed with' their neutral'axes in geodetic lines and being 's'o arranged that the bracing membersin one series intersect the bracing members in the other; means forsecuring the bracing members to ea'ch other where they intersect, boomsinter-l secting sai'd bracing members, and means for se'-A curing thebracing members to saidbooms.

2. An aircraft wing structure having at Aeach upper andlower surface twoseries of symmetrical bracing members shaped to correspond with thecontour of the wing having a greater depth than breadth and having theirdepth normal to the contour at all points, said bracing membersrgb-steigt poriisfmtrseeting said bfa'ti'ng membersandmeansffor"'securing-ithe-bracing members` to f saidy Us: ml, A 3Lff`Anaircraftwing structurehaviri'gat each lppe'r 4and* lower surfaceTtti/eil'series'j of bracing' members shaped to corresponduwith thecontour of 'the wing having Fa'greater depth than breadthand havingtheir "depth normal 'to1 vthe lcontour at7"a`1l points; saidbracingmember's beingA formed vvith-` their' heutral'axes vgeodeticlinesand being' so arranged that the'bracingfmembers in one seriesintersect the 'bracing' members in the other means for securingt-he`*bracing imembrs to ea'ch otherV where theyintersect, *upper* and'lower booms intersecting said braciiig membersymeans directlyinterconnecting said upper Y and Ylower looms,A and means fr's'ecuringthe bracing mem'- berstoysaid'blsf' `41An` aircraftwing'structurehav-ing at each5r i upper and lower surfacetwo series {of'ibracingmembers shaped to correspond with' the contoiir` of*` the wing having agreater depth than-beaiitii and having their" depthnormall'tojthefciitour rat all points, rsaidbracing 'm'embr'slfbeing' soarranged that Ithe bracing'members in 'oiieseries intersect thebracingmer'nbers inthe other, with' theV bracing membersy i` ch seriesconstructed insections extending from one point of intersection to thenext and having their neutral axes in geodetic lines; means for securingthe sections in each series one to another and to the sections of theother series where they intersect,

booms intersecting said sections, and means for arranged that thebracing members in one series intersect the bracing members in theother, with the bracing members in each series` constructed in sectionsextending from one point of intersection to the next and having theirneutral axes in geodetic lines; intersecting fittings `for securi ingthe sections in each series one to another and to the sections of theother series where they intersect, upper and lower boomsintersectingsaid sections, means directly interconnecting said upper and lowerbooms, and boom ttings for securing the sections to the booms.

6. An aircraft wing structure having at each upper and lower surface twoseries of channelsection bracing members-shaped to correspond with thecontour of the wing having webs of a greater depth than the breadth ofthe flanges and having the webs normal to the contour at all points,said bracing members being so arranged that the bracing members in oneseries intersect the bracing members in the other, with the bracingmembers in each series constructed in sections extending from one pointof intersection to the next and having their neutral axes in geodeticlines; means for securing the sections in each series one to another andto the sections of the other series where `they intersect, upper andlower booms intersecting said sections, means directly interconnectingsaid upper and lower booms, and means for securing the sections to saidbooms. i

7. An aircraft wing structure having at each `upper and lower surfacetwo series of channelsection bracing members shaped to correspondgreater"depthj than the"breadthiof their.:` flanges and having' the websnormal to :the contour at all points, said bracing members being soarranged that-the bracing members in oneseries intersect the f bracing fmembers in the' other, withV the bracing members iin `each seriesconstructedin sections extending from one point of intersectionto thenext and having their `neutral axes in geodeticlines; intersectingiittings'for securing the sections in each series onerto another and tothe sectionsofthe other' series Where they intersecti--boo'mslintersecting said sections, and boorri'fttingslor securing the sectionsto said bc'omsfisaid :sectionsxf'having their "webs and anges ttingagainst andattached to jthe inter' sectingiittingsand the'boom'iittingsl V "8.`An aircraftwing structure having at each upperand' lowersurface two series of bracingV memb'ershsl'iape'dtovcorrespond with 'the contour ofthe wing having a greater depth thanbreadth, ai'dlhaving their depth normal to the contour at" all points,said bracing members being so arranged that the bracing Amembers in oneseries intersect the' bracing membersiin the other,` with the bracingmembers in each series constructed in sections extending from one pointof intrsection to the next'and having their neutral axes i i'n'geodeticlines; `intersecting fittings for securing the sections in each seriesone to another and to the sections of the other series where theyintersect, upper and lower booms intersecting said sections, meansdirectly interconnecting said upper and lower booms, and boom fittingson each boom, each consisting of two side plates and a web having anelliptical hole therein for the boom, said boom fittings being fixed tothe boom and to the sections intersecting the boom.

9. An aircraft wing structure having at each upper and lower surface twoseries of bracing members shaped to correspond with the contour of thewing having a greater depth than breadth and having their depth normalto the contour at all points, said bracing members being so arrangedthat the bracing members in one series intersect the bracing members inthe other, with the bracing members in each series constructed insections extending from one point of intersection to the next and havingtheir neutral axes in geodetic lines; intersecting fittings for securingthe sections in each series one to another and to the sections of theother series where they intersect, booms intersecting said sections, andboom fittings on each boom, each consisting of two side plates havingpressed out llets therein and a web having an elliptical hole thereinforthe boom, said boom ttings being fixed to the boom and to the sectionsintersecting the boom.

10. An aircraft wing structure comprising in combination upper and lowerbooms in the deepest portion of the wing; a leading edge boom; atrailing edge boom, said booms al1 extending in the direction of span;means directly interconnecting-said upper and lower booms; two series ofbracing members at each upper and lower surface of the wing shaped tocorrespond with the contour of the wing having a greater depth thanbreadth and having their depth normal to the contour at all points, saidbracing members being arranged in two series which intersect each otherand intersect the booms, with the bracing members in each seriesconstructed in sections extending from one point of intersection to thenext and having their neutral axes in geodetic lines; means for securingthe sections in each seriesxone to another and to the sections of theother series where they intersect; and means for securing the sectionsto the booms.

11. An aircraft wing structure compri-singin combination upper and lowerbooms extending inl the direction ofv span in the deepest portion of,thewing; a leading edge boom extending in the ,direction of spanadjacent to but spaced apart from a leading edge of the wing; a trailingedge boom extending in thedirection-of span adjacent to but spaced apartfrom a trailing edge of the wing; two series of bracing members at eachupper and lower surface ofthe wing shaped to correspond with the contourof theswing having aA greater depth than breadth and having their depthnormal tothe contour at all points, said bracing members being formedwith their neutral axes in geodetic lines and being arranged in twoseries which intersect each other and in tersect the booms; means forsecuring the bracing members to each other where they intersect; meansfor securing the bracing members to the booms; and fairings iixed to theleading and trailing edge booms adapted to form the leading and trailingedges.

l2. An aircraft wing structure comprising in combination upper and lowerbooms extending inthe direction of span in the the deepest portion ofthe wing; a leading edge boomextending in the direction of spanadjacent; to but spaced apart from a leading edge of the wing; atrailing edge boom extending in the direction of Vspan adjacent to butspaced apart from a trailing edge of the wing; upper and lower sets ofbracing members, the upper 4set shaped to correspond with the uppercontour of the` wing, and the lower set with the lower contour of thewing between said booms, having a greater depth than breadth and havingtheir depth normal to the contour at all points, saidbracing membersbeing formed with their neutral axesvin geodetic linesv and beingarranged in two series which intersect each other and intersect thebooms; means for; securing the bracing members to each other where theyintersect; means lfor. securing the bracing members to the booms withwhich they intersect; channels constituting parts of*` said leading andtrailing edgebooms for receiving and securing the bracingmembers whichintersect these booms; knee piecesv for connecting upper. and lowerbracing members to each other and to leading and trailing edge booms attheir points of connection; and fairings xed -to the leading andtrailing edge booms adapted to form the leading and trailing edges.

. BARNES NEVILLE WALLIS.

